Embodiments of the invention relate to a vehicle having at least one vehicle door or vehicle flap which forms a first body and having a vehicle bodyshell which forms a second body.
In a vehicle, the vehicle door or vehicle flap (bodyshell flap of a vehicle) is normally pivotably attached to the vehicle bodyshell and, in the closed state, can be fixed to the bodyshell by way of at least one lock on the vehicle bodyshell, which lock interacts with a closing element, for example a lock striker or a catch. A vehicle of said type is equipped with an impact damper arrangement for damping impacts between the vehicle bodyshell and the vehicle door or vehicle flap during the closing of the vehicle door or vehicle flap, wherein the impact damper arrangement has a damping device which is arranged so as to act between the vehicle bodyshell and the vehicle door or vehicle flap and which has a first movement section, in which damping is performed, and a second movement section, in which no damping is performed.
During the closing of a front flap of a vehicle, for example, said front flap can, if closed with too much force, strike the headlamps and the front paneling (kidney grille). Therefore, until now, it has been necessary for interstices to be provided between the front flap and the headlamps or the front paneling, which interstices are large enough to prevent damage as a result of such impacting. A minimum interstice may in this case be approximately 3.5 mm (that is to say nominally approximately 5.3 mm±1.8 mm). For visual reasons in particular, however, it is sought for said interstices between front flap and front paneling to be made ever smaller.
Furthermore, a minimum closing speed of approximately 1.2 to 1.5 m/s is necessary for the lock or locks in order to securely close the front flap. Damage to components such as radiator grille, headlamps, bumpers and/or side wall may arise already at a speed of 2.5 to 3.0 m/s (“misuse speed”). Furthermore, such impacting of the front flap can also give rise to inadvertent and unnoticed adjustment of the headlamp setting.
In general, it is therefore the case that damping of the movement of the front flap (or else of doors or other bodyshell flaps of a vehicle) is performed before it strikes the lock. It is for example possible for locks with damping action, retraction-damped gas springs, and buffers with damping action to be used for this purpose.
Elements integrated in the lock can effect a damping action until the vehicle flap is almost closed. This therefore requires a large amount of closing energy, and the damping is performed only shortly before lock contact occurs. For example, a closing speed of approximately 2 m/s (with damper) may be necessary for secure closure (approximately 1.5 m/s without damper).
In the case of gas springs, in particular retraction-damped gas springs, leading damping is performed. Such gas springs are however of low effectiveness and therefore do not ensure optimum damping. Furthermore, such gas springs are expensive.
In the case of conventional front flap locks, the front flap is raised by approximately 20 to 35 mm for the purposes of opening front flap. This corresponds to the “catch position”. Vehicles with air inlets integrated into the front flap may furthermore have a deployable handle for raising the front flap. This is however not possible in the case of front flaps which have a cut-in or overlying configuration, such as are often used.
The above damping systems have disadvantages insofar as the damping begins only when the lock and lock striker are already in engagement, or shortly before the engagement. Since the damping begins at a late point in time, it is also the case that damping is performed during the closing process, and thus the closing convenience is impaired. In this way, the user is motivated to close the front flap with high force. Furthermore, the range between minimum closing speed and impacting over travel may be small, in particular owing to the requirement for the small gap widths. In this way, impacting over travel of the flap such that it impacts against adjacent components is possible, in particular if the front flap is closed with high force.
DE 10 2004 008 046 A1 has disclosed a stop buffer for a vehicle door or vehicle flap, which stop buffer has a main body composed of an elastic material, wherein, in the main body, there is situated at least one cavity which is preferably completely filled with a liquid. During the deformation of the stop buffer, energy is absorbed owing to the elasticity of the elastic material and the viscosity of the filling. For this purpose, during the closing of the vehicle door or vehicle flap, a pressure fluid is forced from a first chamber of the stop buffer into a second chamber through an opening provided in a diaphragm. Here, during the compression, a valve body which is equipped with axial channels and which tapers to a point is moved into the diaphragm opening, whereby the opening cross section is reduced, and thus the damping force increases.
DE 103 60 833 A1 relates to a gas spring for a front flap of a vehicle. In said document, the stated problem is described as being that conventional gas springs, which support the weight of a front flap during opening or closing of the front flap, have the disadvantage that, in the case of a collision of a cyclist or a pedestrian against the front flap, a spring force action of the gas spring still exists which impedes a yielding of the front flap in the region of the connection of the gas spring owing to the spring force that still exists there. To solve said problem, the gas spring can, in the closed state of the front flap, still perform an additional travel in a compression direction, over which travel only a low level of damping is realized because, in said range of the additional travel, the damping of the gas spring is reduced.
DE 31 50 081 A1 relates to an air pressure impact damper. In said document, it is stated as being a problem that such air pressure impact dampers have a spring-back tendency owing to the compressibility of the air. To solve said problem, the compression chamber of the air pressure impact damper has a connection between the compression chamber and the atmosphere, wherein a throttle valve element is provided in said connection. Via said throttled connection to the atmosphere, it is possible, during the compression of the air pressure impact damper, for air to emerge in controlled fashion from the compression chamber, such that an undesired pressure increase in the compression chamber, which would lead to a rebound of the piston, does not occur.
FR 2 751 714 A1 has a brake system for a unit composed of two mobile elements. Said brake system is provided for example for a vehicle ashtray that can be deployed out of a receiving device. The movable part of the vehicle ashtray is forced into the open position under the action of a spring. A gearwheel-toothed rack arrangement acts as a brake element, wherein the gearwheel that is in engagement with toothed racks acts as a friction brake. The gearwheel engages with the toothed racks not over the entire movement travel of the ashtray but only during the deployment of the ashtray. In the retracted state and in the deployed state, the gearwheel is not in engagement with the toothed racks. In the closed position of the ashtray, in which a locking element (not described in any more detail) is active, the ashtray is subjected to the full pressure action of the spring force, whereas the gearwheel that acts as brake element is not in engagement with the toothed racks. In this closed state, it is thus the case that the movable part of the ashtray is subjected to the spring force, which must be supported by the locking element. Accordingly, the spring force acts on the ashtray even during the pushing-in process and during the locking process. The pushing-in movement is thus damped, until locking has taken place, by the spring force that counteracts said pushing-in movement.
JP 2010-228 675 A presents a stopper for a hood, which stopper is intended, by way of the movement of an impact-absorbing movable element, to absorb the impact that occurs during the closing of the hood. Said impact-absorbing element may be provided either on the hood or on a vehicle bodyshell. A movable plunger which is equipped with a piston is movable into a cylindrical plunger receptacle counter to the force of a spring. In one variant, the spring, which runs in a direction of movement of the plunger, is bent inwardly into the cylinder such that the plunger is moved beyond a spring dead center, wherein, in the beyond-dead-center position, said plunger is retracted further by the spring. The time at which the piston-like plunger is pulled into the receptacle by the spring is not specified.
U.S. Pat. No. 5,697,477 A presents and describes an air spring damper which is designed as a piston-cylinder unit and which can be used for example as a damper for the glove compartment cover in an automobile. The mode of operation of said damper consists in that, during the movement of the piston, air flows from the chamber situated on one side of the piston, the volume of which chamber is decreased in size during the movement, through a throttle opening in the piston into the other chamber situated on the other side of the piston, which chamber is increased in size during the movement of the piston. The intensity of the damping is determined by the size of the throttle opening. An O-ring is inserted as a piston ring into a groove on the circumference of the piston and, by way of its friction exerted on the cylinder wall during the movement of the piston, likewise generates a braking force of the piston movement. Shortly before the maximally deployed position of the piston rod connected to the piston is reached, the piston passes into a region of the cylinder in which the diameter of the cylinder wall gradually decreases slightly, such that the friction force that acts between the O-ring and the cylinder wall is intensified, whereby the braking force that is exerted on the piston movement is also intensified. The opening movement of the glove compartment cover is thus braked shortly before the maximally opened position of the glove compartment cover is reached. In addition to the throttle opening in the piston, it is possible for axial grooves to be provided in the cylinder wall, which axial grooves likewise allow the air to flow past the piston during the movement thereof. Said axial grooves are however not provided in the region in which the cylinder wall narrows, such that, there, the full braking action described above is maintained. The damper presented and described here serves for damping the opening movement of the flap.
DE 201 07 426 U1 describes a brake regulator with air or liquid damping. A brake regulator of said type is provided in particular for end position damping of drawers or doors. Said brake regulator is designed as a piston-cylinder unit, wherein, in a region of the cylinder wall, there may be provided an axial groove through which air can flow past the piston from the air chamber formed on one side of the piston into the air chamber formed on the other side of the piston. Furthermore, it is also the case that a flow opening formed in the manner of a check valve is provided in the piston. During the compression of the piston-cylinder unit, said check valve is closed, and the air in the cylinder chamber situated in front of the piston is compressed, whereby a damping force is built up. When the piston reaches the region of the cylinder in which the axial groove is provided in the cylinder wall, it is possible for air to flow past the piston from the compression chamber into the air chamber behind the piston, and the damping force is reduced. Shortly before the maximally retracted position of the piston is reached, a further air outflow groove is provided in the cylinder wall, through which air outflow groove a further dissipation of pressure in the compression chamber is then realized. Said further pressure dissipation is intended to take place such that the positive pressure in the compression chamber is abruptly fully dissipated. In this final travel segment of the piston, there is thus no longer a damping force. As a result of said abrupt dissipation of the damping force in the end position of the piston, it is achieved that the compression movement of the piston-cylinder unit at the end of the piston movement does not lead to a recoil reaction owing to the positive pressure in the compression chamber.
EP 0 334 253 A1 presents and describes a gas spring which, for the purposes of supporting the weight of a movable component, for example of a luggage compartment flap, is provided in a motor vehicle between the bodyshell of the motor vehicle and the movable structural element. There, a device for controlling the reaction forces of the gas spring is provided, which device has the effect that, when the movable component (for example the luggage compartment flap) is closed, that is to say the gas spring is situated in its compressed state, the gas spring no longer exerts spring-induced pressure forces on the luggage compartment flap. Shortly before the complete closure of the luggage compartment flap, a spring plate, which is acted on by the spring force, of the gas spring runs against a stop provided on the bodyshell, and is supported on said stop. The spring force of the gas spring, which is fastened by way of its upper end to the body, is, in the completely closed state of the vehicle flap, introduced into the vehicle bodyshell again via the stop, such that, in the closed state of the vehicle flap, no spring force acts on the structure of the vehicle flap.
It is an object of the embodiments of the present invention to provide a vehicle having a vehicle bodyshell and at least one vehicle door or vehicle flap with an impact damping arrangement for damping impacts between the vehicle bodyshell and the vehicle door or vehicle flap, in the case of which vehicle at least one or more of the abovementioned disadvantages are reduced or substantially do not arise, and in the case of which vehicle, in particular, the risk of impacting of a front flap against the headlamps is prevented.
Accordingly, it is provided in this regard that the impact damper arrangement is designed such that, when the vehicle door or vehicle flap moves toward the vehicle bodyshell, the first movement section is passed through first, and then the second movement section is passed through, wherein the first movement section is arranged such that the movement along the first movement section comes to an end when the lock and the closing element come into contact with one another.
By way of the solution according to the invention, it is possible for the closing speed to be braked to a minimum speed required for the closing function in the lock, and to nevertheless ensure a secure engagement of the closing element into the lock. The closing speed is thus damped before, and only up until the point at which, the closing element strikes the lock. The operator is thus not incited to close the vehicle flap with particularly high force. The damping may also be realized in speed-dependent fashion in order to ensure that, regardless of the closing speed imparted by the operator, the minimum speed required for the reliable closure of the lock is always attained at the end of the damping, that is to say at the end of the first movement section.
Preferred embodiments and particular aspects of the embodiments of the invention will emerge from the drawings and from the present description.
According to a further aspect, a method for damping impacts between a vehicle bodyshell and a vehicle door or vehicle flap in a vehicle is specified. The method includes the steps of passing through a first movement section of the damping device, in which damping is performed, until the lock and the closing element come into contact with one another, and subsequently passing through a second movement section of the damping device, in which no damping is performed.
The provision of an impact damper arrangement according to the embodiments described here offers travel-dependent damping, and in particular travel-dependent and speed-dependent damping. In this way, damage to the first and/or second body, which are for example locked to one another but are not intended to be brought into direct contact, can be prevented. At the same time, by way of the second movement section, which does not exhibit damping, an amount of residual impact energy can be provided which is sufficient, for example, to ensure secure and reliable non-positive and/or positive engagement of the closing element with the lock.
Here, the damping begins at an early point in time and may for example come to an end approximately at the point of initial contact of the closing element with the lock. The damping travel prior to the striking of the lock can be increased in relation to conventional impact damper arrangements (e.g. 50 mm). The damping acts only prior to the time at which the lock and closing element come into contact. The speed can thus be reduced to such an extent that only the closing speed of the lock, at which the lock securely closes, remains. The impact damper arrangement according to the embodiments described here thus offers travel-dependent and speed-dependent damping.
In vehicles, it is thus possible to avoid a situation in which a long (e.g. 50 mm) plunger of the impact damper arrangement protrudes out of the flap or vehicle structure. In particular, one part (e.g. a rubber pin) may be situated on the flap, and the counterpart (the damping device, which includes the damping means) may be recessed in the bodyshell. It is thus possible for the plunger stroke to be split up, and no excessively long plunger is visible to the user. In embodiments described here, an interstice reduction on the vehicle is also possible, which, inter alia, yields an appealing appearance, because small interstices (bodyshell gaps) are regarded by the purchaser of the vehicle as being a high-quality characteristic.
Other objects, advantages and novel features of the embodiments of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.